The LED would still turn on, even if the PSU is dead. This was the case with my 850w, when everything was plugged in, the LED goes on, but when I power it up, the fans will spin for a second or so, and turn off.Yeah, that's what I'm doing but it doesn't seem to be working. Might I ask, if it were the PSU malfunctioning, then why does the blue LED by the 24-pin connector come on when I switch on the PSU (indicating that there is power to the motherboard)?
And actually I went to the store and paid in cash for the thing, would they be able to retrieve a new invoice for me given that scenario?
They might be able to find your invoice, if you remember the exact date you bought it.